A141343 Riordan array (1,x/sqrt(2-sqrt(1+4x))).

1, 0, 1, 0, 2, 1, 0, 2, 4, 1, 0, 4, 8, 6, 1, 0, 2, 16, 18, 8, 1, 0, 12, 24, 44, 32, 10, 1, 0, -12, 48, 90, 96, 50, 12, 1, 0, 72, 48, 180, 240, 180, 72, 14, 1, 0, -190, 160, 308, 544, 530, 304, 98, 16, 1, 0, 700, -40, 600, 1120, 1372, 1032, 476, 128

Offset

0,5

Comments

Factorizes as (1,xc(-x))*(1,x(1+x)/(1-2x)) where c(x) is the g.f. of A000108.

Row sums are A141344.

Triangle T(n,k), 0<=k<=n, read by rows, given by [0, 2, -1, -1, -1, -1, -1, -1, -1, ...] DELTA [1, 0, 0, 0, 0, 0, 0, ...] where DELTA is the operator defined in A084938. - Philippe Deléham, Nov 15 2008

Links

Table of n, a(n) for n=0..63.

Example

Triangle begins
1,
0, 1,
0, 2, 1,
0, 2, 4, 1,
0, 4, 8, 6, 1,
0, 2, 16, 18, 8, 1,
0, 12, 24, 44, 32, 10, 1,
0, -12, 48, 90, 96, 50, 12, 1

Crossrefs

Sequence in context: A227341 A098542 A320019 * A256678 A066709 A258051

Adjacent sequences: A141340 A141341 A141342 * A141344 A141345 A141346

Keyword

easy,sign,tabl

Author

Paul Barry, Jun 26 2008

Status

approved